Final answer:
Cretinism is a condition of arrested physical and mental development caused by a congenital lack of thyroid secretion. It is characterized by dwarfism, thick tongue and skin, cognitive deficits, andsexual undevelopment.
Step-by-step explanation:
A congenital lack of thyroid secretion in children results in cretinism, a condition characterized by arrested physical and mental development. Symptoms include dwarfism, thick tongue and skin, cognitive deficits, and sexual undevelopment. In adults, hypothyroidism leads to myxoedema, which is characterized by thick, dry and waxy skin, dull mental ability, and sensitivity to cold.